Structural characterization of a novel KH-domain containing plant chloroplast endonuclease
| Autor: | Renu Minda, Vandana Raghvan, Sunita Patel, Basuthkar J. Rao, Himanshu Singh, Saurabh Gautam, Ashok K. Rout, Kandala V. R. Chary |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Chloroplasts Mutant lcsh:Medicine Chlamydomonas reinhardtii Article 03 medical and health sciences chemistry.chemical_compound Endonuclease Protein Domains Cell Wall Catalytic triad Amino Acid Sequence lcsh:Science Nuclear Magnetic Resonance Biomolecular Plant Proteins Multidisciplinary biology lcsh:R Endonucleases biology.organism_classification KH domain Chloroplast 030104 developmental biology chemistry Plant protein biology.protein Biophysics lcsh:Q DNA |
| Zdroj: | Scientific Reports Scientific Reports, Vol 8, Iss 1, Pp 1-14 (2018) |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-018-31142-w |
| Popis: | Chlamydomonas reinhardtii is a single celled alga that undergoes apoptosis in response to UV-C irradiation. UVI31+, a novel UV-inducible DNA endonuclease in C. reinhardtii, which normally localizes near cell wall and pyrenoid regions, gets redistributed into punctate foci within the whole chloroplast, away from the pyrenoid, upon UV-stress. Solution NMR structure of the first putative UV inducible endonuclease UVI31+ revealed an α1–β1–β2–α2–α3–β3 fold similar to BolA and type II KH-domain ubiquitous protein families. Three α−helices of UVI31+ constitute one side of the protein surface, which are packed to the other side, made of three-stranded β–sheet, with intervening hydrophobic residues. A twenty-three residues long polypeptide stretch (D54-H76) connecting β1 and β2 strands is found to be highly flexible. Interestingly, UVI31+ recognizes the DNA primarily through its β–sheet. We propose that the catalytic triad residues involving Ser114, His95 and Thr116 facilitate DNA endonuclease activity of UVI31+. Further, decreased endonuclease activity of the S114A mutant is consistent with the direct participation of Ser114 in the catalysis. This study provides the first structural description of a plant chloroplast endonuclease that is regulated by UV-stress response. |
| Databáze: | OpenAIRE |
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